Context: Data on the adverse effects of newly marketed drugs are limited. Voluntary reporting is an important part of postmarketing surveillance but is underused by physicians.
Objective: To evaluate the effectiveness of educational outreach visits for improving adverse drug reaction (ADR) reporting by physicians.
Design, setting, and participants: A cluster-randomized controlled trial covering all National Health System physicians in the north of Portugal, with intervention in March 2004 through July 2004, and 13 to 16 months of follow-up. A total of 1388 physicians were assigned in 4 spatial clusters to the intervention group, and 5063 were assigned in 11 clusters to the control group.
Intervention: One-hour educational outreach visits tailored to training needs identified in a previous study.
Main outcome measures: Change in total number of reported ADRs and number of serious, high-causality, unexpected, and new-drug-related ADRs, using generalized linear mixed models adjusted for baseline ADR reporting, age, specialty, and work setting.
Results: At baseline, ADR reporting rates (per 1000 physician-years) did not differ significantly between the intervention groups and the control groups in reporting ADRs overall (7.6 vs 11.3), nor did they differ significantly by category: serious, 4.3 vs 6.0; high-causality, 5.4 vs 7.6; unexpected, 1.6 vs 3.5; and new-drug-related ADRs, 3.7 vs 3.8. (P>.05 for all comparisons). The control group had no significant increase in ADR reports during follow-up. The adjusted increase in ADR reporting rates attributable to intervention was 90.19 for total ADRs (95% confidence interval [CI], 54.51-125.87; relative risk [RR], 10.23; 95% CI, 3.81-27.51), 30.16 for serious ADRs (95% CI, 18.84-41.47; RR, 6.32; 95% CI, 2.09-19.16), 64.90 for high-causality ADRs (95% CI, 38.38-91.42; RR, 8.75; 95% CI, 3.05-25.07), 28.04 for unexpected ADRs (95% CI, 16.25-39.83; RR, 30.21; 95% CI, 4.54-200.84), and 42.17 for new-drug-related ADRs (95% CI, 21.58-62.76; RR, 8.05; 95% CI, 2.10 -30.83). The greatest difference occurred during the first 4 months after intervention, but differences remained statistically significant for 12 months.
Conclusion: A targeted outreach program may improve high-quality reporting of ADRs among physicians.